http://www.coldhardfootballfacts.co...t-filled_history_of_the_NFL_passing_game.html
The Golden Age (2004-present)
As if quarterbacks hadn’t been coddled enough by coaches and rulemakers over the past two decades, one profound game, and one very angry team executive, made their lives even easier in 2004.
One, New England defenders pushed the bounds of pass interference rules in the 2003 AFC championship game, badly roughing up Indianapolis receivers and shutting down the Colts high-powered offense in a 24-14 Patriots victory.
Two, Indy’s powerful president, Bill Polian, complained to the league rather loudly in the wake of his team's loss.
As a result, the NFL determined that its officials would “re-emphasize” pass interference rules in 2004 and beyond. Though not officially a rule change, the impact on the passing game was profound.
The very next season, Indy quarterback Peyton Manning (pictured here) went out and rewrote the record books, with 49 TD passes and a 121.1 passer rating that was nearly 10 points better than any that had come before it. The league-wide passer rating, meanwhile, jumped from 78.3 in 2003 to a record 82.8 in 2004.
The records have remained under assault since then: Tom Brady broke Manning’s TD-toss record with 50 in 2007, while posting the second-highest passer rating in history (117.2). With less fanfare, Drew Brees set a record with 440 completions in 2007. And, as noted above, NFL quarterbacks are poised to rewrite the record books in countless categories here in 2008, while newcomers have bucked tradition by easily performing at high level.
But today's high-flying newcomers and record-setting veterans aren't better quarterbacks than players of the past. They just have advantages their predecessors never enjoyed back before the Golden Age of the passing game.